Investment in Kronos Worldwide, Inc. - Changes in Carrying Value of Investment (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Balance at the beginning of the period	$ 248,355
Equity in earnings of Kronos Worldwide, Inc.	8,207	$ 9,225
Dividends received from Kronos	(6,339)	$ (6,339)
Equity in Kronos' other comprehensive income:
Balance at the end of the period	238,067
Kronos
Balance at the beginning of the period	248,400
Equity in earnings of Kronos Worldwide, Inc.	8,200
Dividends received from Kronos	(6,300)
Equity in Kronos' other comprehensive income:
Currency translation	(12,800)
Other	(300)
Balance at the end of the period	238,100
Kronos \| Defined Benefit Pension Plans
Equity in Kronos' other comprehensive income:
Defined benefit pension plans	$ 900

Other comprehensive income loss other before tax.

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Amount before tax, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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